Impact of the Endonaut® Angio-Navigation System on Radiation Exposure in Endovascular Aortic Repair Performed with Mobile C-Arms.

BACKGROUND: Fusion imaging systems have proved to reduce radiation exposure mostly in hybrid rooms but reports with mobile C-arms are few. The aim of this study was to analyze the impact of the Endonaut navigation system on radiation exposure in endovascular aneurysm repair (EVAR) performed with mobile C-arms. METHODS: All patients undergoing EVAR and/or iliac branched devices implantation between January 2016 and August 2022 were included. All procedures were performed with a mobile C-arm (Siemens Avantic or GE Elite until March 2018, Siemens Cios Alpha thereafter). The Endonaut navigation system has been used since January 2021. Two groups were, therefore, compared: before (control group [CGr]) and after the use of Endonaut. Radiation data including Dose Area Product (DAP) values, Air Kerma (AK) and fluoroscopy time (FT) were collected retrospectively. RESULTS: Overall, 153 patients were included: CGr, n = 121; Endonaut group (EnGr), n = 32. No significant difference was found between the 2 groups regarding demographic data. DAP values were significantly lower in the EnGr (38 Gy cm2 ± 24) vs. the CGr (76 Gy cm2 ± 51) (P < 0.05) despite a significantly higher number of complex procedures such as iliac branched devices (P < 0.05). AK values were not significantly different between the EnGr and the CGr (196 mGy ±114 vs. 209 mGy ±138) as well as FT (33 minutes ±18 vs. 33 minutes ±16). Technical success was 97% (31/32) in the EnGr vs. 96% (116/121) in the CGr (P = 0.79). The volume of contrast media was significantly lower in the EnGr (94 cc ± 41) vs. the CGr (143 cc ± 66) (P < 0.05). CONCLUSIONS: In this study, the use of the Endonaut angio-navigation system when performing EVAR with mobile C-arms led to a radiation dose reduction without compromising technical success or procedural time.

Unraveling Renal Arteries Morphogenesis from Tridimensional Human Embryos Reconstruction.

BACKGROUND: During human morphogenesis, the definitive kidneys derive from the metanephros during Carnegie Stage 14 to 23. The pronephros and the mesonephros develop previously and successively to finally lead to the formation of the urinary tract. Renal vascularization, first described in 1912 by Félix using a "ladder theory" model, is highly variable and current available morphogenesis descriptions do not explain all reported anatomical variations. The aim of this work was to study the morphogenesis of the human metanephros and its vascularization by three-dimensional reconstructions of human embryos. METHODS: Histological sections of 23 human embryos from the Carnegie Collection and 5 human embryos from the French collection (Carnegie stages 14 to 23) were completely digitalized and reconstructed in three dimensions using specific softwares and then analyzed by descriptive method using manual annotation. RESULTS: In all studied embryos, the mesonephric arteries did not reach the metanephros irrespective to the position of the metanephros during its cranial ascent. Before the end of the cranial metanephros migration (15 embryos), at the level of the aorto-iliac bifurcation, a "primitive" vascularization was shown in 9 of them. The renal artery originated from the primitive iliac arteries for 8 embryos and from the inferior mesenteric artery in one embryo. Further, a capillary cluster emerging from the lateral wall of the aorta and extending toward the metanephros was found in 2 embryos (Carnegie stages 21 and 22). This may correspond to a phenomenon of neoangiogenesis responsible of the definitive renal artery. CONCLUSIONS: The present study reported the morphogenesis of human renal arteries between Carnegie stages 14 and 23 using an original method of tridimensional computerized reconstructions of historical human embryos. Some original findings, in contradiction with the original Felix's description, may explain the most frequently reported anatomical variations.

Multicentre Evaluation of an Extra Low Dose Protocol to Reduce Radiation Exposure in Superior Mesenteric Artery Stenting.

OBJECTIVE: Radiation dose in mesenteric stenting (MS) remains under evaluated. Yet, MS can lead to high levels of radiation mainly because lateral angulation is needed. The aim of this study was to evaluate the efficacy of an extra low dose protocol (ELDP) to reduce radiation exposure in MS. METHODS: From November 2017 to November 2019, all patients presenting with either acute or chronic atherosclerotic mesenteric ischaemia treated by antegrade MS using either fixed or mobile imaging systems in three university hospitals were included. In November 2018, an ELDP including ≤3 frames/s fluoroscopy and digital subtraction angiography (DSA) was introduced. Prospectively enrolled ELDP patients (Nov 2018-Nov 2019) were compared with retrospectively captured patients (Historical group, Nov 2017-Nov 2018). Radiation data including dose area product (DAP), cumulative air kerma (CAK), and fluoroscopy time (FT) were analysed. RESULTS: Overall, 46 patients (median age 73 years [63-72], 59% males) were included (ELDP group, n = 21; Historical group, n = 25). Thirty-three patients (72%) underwent MS in a hybrid room. Median DAP (ELDP group, 10 [4.7-26] Gy.cm2vs. Historical group, 45 [24-88] Gy.cm2, p = .002), median CAK (ELDP group, 170 [58-260] vs. Historical group, 262 [152-460], p = .037), and median number of DSA runs (ELDP group, 4 [1.5-5] vs. Historical group, 5.5 [3.7-5], p = .030) were statistically significantly lower in patients receiving the ELDP, whereas median FT (ELDP group, 16 min [11-23] vs. Historical group, 14 min [9-25], p = .71) and technical success (ELDP group, 95%; Historical group, 92%, p = .65) were not statistically significantly different between groups. CONCLUSION: MS exposes both patients and physicians to a high ionising radiation dose. Awareness of radiation safety and seeking dose reduction is paramount in these highly irradiating procedures. The use of ELDP significantly reduces radiation without compromising technical success.

Comparison of Cryopreserved Arterial Allografts Versus Heparin-bonded Vascular Grafts in Infragenicular Bypass for Chronic Limb Threatening Ischemia.

BACKGROUND: The purpose of this study was to compare cryopreserved arterial allograft (CAA) to heparin-bonded prosthesis (HBP) in infragenicular bypasses for patients with chronic limb-threatening ischemia (CLTI). METHODS: This retrospective study took place in 2 university hospitals and included 41 consecutive patients treated for CLTI. In the absence of a suitable saphenous vein, an infragenicular bypass was performed using either CAA (24 cases) or HBP (17 cases). Kaplan-Meyer analysis compared primary and secondary patency and amputation-free survival rates. Binomial logistic regression analyzed risk factors for major amputation and thrombosis. RESULTS: The mean followup was 18.5 months (±14.3) in the CAA group, 17.6 (±6.1) in the HBP group. In the CAA group, primary and secondary patency rates at 12 months were 52% (±10.6) and 61% (±10.3), compared to 88% (±7.8) and 94% (±5.7) in the HBP group, respectively. The difference in patency rates was not statistically different (P = 0.27 and P = 0.28, respectively). The statistically significant factors of graft thrombosis were, a stage 4 from the WIfI classification (Wound Ischemia foot Infection) with a 6 times higher risk (P = 0.04), and a distal anastomosis on a leg artery with a 9 times higher risk of thrombosis (P = 0.03). Amputation-free survival rates at 18 months were similar between the groups (CCA: 75% (±9) versus HBP: 94% (±6), P = 0.11). Patients classified as WIfI stage 4 had 13 times higher odds to undergo major amputation than patients with WIfI stage 2 or 3 (95% CI, 1.16-160.93; P = 0.04). The intervention was longer in the CCA group of 74 min (278 min ± 86) compared to the HBP group (203 min ± 69). This difference was statistically significant (95% CI, 17.86-132.98), t(35) = 2.671, P = 0.01. CONCLUSIONS: CCA is not superior to HBP in infragenicular bypasses for CLTI, and may not be worth the extra cost and the longer operative duration.

Lower Rate of Restenosis and Reinterventions With Covered vs Bare Metal Stents Following Innominate Artery Stenting.

PURPOSE: To determine any difference between bare metal stents (BMS) and balloon-expandable covered stents in the treatment of innominate artery atheromatous lesions. MATERIALS AND METHODS: A multicenter retrospective study involving 13 university hospitals in France collected 93 patients (mean age 63.2±11.1 years; 57 men) treated over a 10-year period. All patients had systolic blood pressure asymmetry >15 mm Hg and were either asymptomatic (39, 42%) or had carotid (20, 22%), vertebrobasilar (24, 26%), and/or brachial (20, 22%) symptoms. Innominate artery stenosis ranged from 50% to 70% in 4 (4%) symptomatic cases and between 70% and 90% in 52 (56%) cases; 28 (30%) lesions were preocclusive and 8 (9%) were occluded. One (1%) severely symptomatic patient had a <50% stenosis. Demographic characteristics, operative indications, and procedure details were compared between the covered (36, 39%) and BMS (57, 61%) groups. Multivariate analysis was performed to determine relative risks of restenosis and reinterventions [reported with 95% confidence intervals (CI)]. RESULTS: The endovascular procedures were performed mainly via retrograde carotid access (75, 81%). Perioperative strokes occurred in 4 (4.3%) patients. During the mean 34.5±31.2-month follow-up, 30 (32%) restenoses were detected and 13 (20%) reinterventions were performed. Relative risks were 6.9 (95% CI 2.2 to 22.2, p=0.001) for restenosis and 14.6 (95% CI 1.8 to 120.8, p=0.004) for reinterventions between BMS and covered stents. The severity of the treated lesions had no influence on the results. CONCLUSION: Patients treated with BMS for innominate artery stenosis have more frequent restenoses and reinterventions than patients treated with covered stents.

Treatment of Complex Aortic Aneurysms Using Combination of Renal and Visceral Bypass and Fenestrated/Branched Stent Grafts.

BACKGROUND: The purpose of this study was to report our experience of treatment of aortic aneurysms using combination of renal and visceral arteries bypasses and fenestrated/branched stent graft in various complex anatomical situations. METHODS: Between November 2005 and March 2017, 10 patients underwent a hybrid strategy combining bypasses for renal and/or visceral arteries and custom-made fenestrated/branched stent grafts. Two patients had abdominal aortic aneurysm (1 juxtarenal and 1 suprarenal), and 8 patients had thoracoabdominal aortic aneurysm (1 type I, 2 type II including one dissection, 2 type III, 1 type IV, and 2 type V). In total, 37 renal and visceral arteries were targeted, of which 23 were treated using fenestrated or branched stent graft and 14 were treated by bypass (11 to renal artery and 3 to celiac trunk). RESULTS: Technical success was 100%, and no patient died during a mean follow-up of 24.3 ± 21 months. Six patients had 7 postoperative complications after bypass surgery, and 3 patients had 3 complications after fenestrated or branched endovascular aneurysm repair (FEVAR/BEVAR) procedure. Seven reinterventions were performed in 3 patients. No occlusion of target vessels occurred. Renal function was stable during follow-up in all patients except one who developed end-stage renal failure requiring permanent dialysis. On the last follow-up computed tomography scan, aneurysm diameter decreased for 6 patients, was stable for 3 patients, and increased for one patient, in which persistent type II endoleak was observed. Aneurysm exclusion was complete in the remaining 9 patients. CONCLUSIONS: Combination of FEVAR/BEVAR procedures with renal and/or visceral artery bypass in patients with complex aortic aneurysms is feasible with acceptable results. Morbidity associated with bypass surgery has to be carefully balanced with the risk of catheterization difficulties in the setting of adverse anatomical features of the visceral/renal arteries or the aorta.

Cryopreserved arterial allografts for in situ reconstruction of abdominal aortic native or secondary graft infection.

OBJECTIVE: The objective of this study was to evaluate the early and long-term outcome of cryopreserved arterial allografts (CAAs) used for in situ reconstruction of abdominal aortic native or secondary graft infection and to identify predictors of mortality. METHODS: We retrospectively included 71 patients (mean age, 65.2 years [range, 41-84 years]; men, 91.5%) treated for abdominal aortic native or secondary graft infection (65 prosthetic graft infections; 16 of them had secondary aortoenteric fistula, 2 venous graft infections, and 4 mycotic aneurysms) by in situ reconstruction with CAA in the university hospitals of Clermont-Ferrand and Saint-Etienne from 2000 to 2016. The cryopreservation protocol was identical in both centers (-140°C). Early (<30 days) and late (>30 days) mortality and morbidity, reinfection, and CAA patency were assessed. Computed tomography was performed in all survivors. Survival was analyzed with the Kaplan-Meier method. Univariate analyses were performed with the log-rank test and multivariate analysis with the Cox regression model. RESULTS: Mean follow-up was 45 months (0-196 months). Early postoperative mortality rate was 16.9% (11/71). Early postoperative CAA-related mortality rate was 2.8% (2/71); both patients died of proximal anastomotic rupture on postoperative days 4 and 15. Early CAA-related reintervention rate was 5.6% (4/71); all had an anastomotic rupture, and two were lethal. Early postoperative reintervention rate was 15.5% (11/71). Intraoperative bacteriologic samples were positive in 56.3%, and 31% had a sole microorganism. Escherichia coli was more frequently identified in the secondary aortoenteric fistula and Staphylococcus epidermidis in the infected prosthesis. Late CAA-related mortality rate was 2.8%: septic shock at 2 months in one patient and proximal anastomosis rupture at 1 year in one patient. Survival at 1 year, 3 years, and 5 years was 75%, 64%, and 54%, respectively. Multivariate analysis identified type 1 diabetes (hazard ratio, 2.49; 95% confidence interval, 1.05-5.88; P = .04) and American Society of Anesthesiologists class 4 (hazard ratio, 2.65; 95% confidence interval, 1.07-6.53; P = .035) as predictors of mortality after in situ CAA reconstruction. Reinfection rate was 4% (3/71). Late CAA-related reintervention rate was 12.7% (9/71): proximal anastomotic rupture in one, CAA branch stenosis/thrombosis in five, ureteral-CAA branch fistula in one, and distal anastomosis false aneurysm in two. Primary patency at 1 year, 3 years, and 5 years was 100%, 93%, and 93%, respectively. Assisted primary patency at 1 year, 3 years, and 5 years was 100%, 96%, and 96%, respectively. No aneurysm or dilation was observed. CONCLUSIONS: The prognosis of native or secondary aortic graft infections is poor. Aortic in situ reconstruction with CAA offers acceptable early and late results. Patients with type 1 diabetes and American Society of Anesthesiologists class 4 are at higher risk of mortality.

Renovascular hypertension: results in adulthood of renal autotransplantation performed in children.

BACKGROUND: This study describes the long-term results of renal autotransplantation for renovascular hypertension performed in children who are now 21 years of age or older. METHODS: Sixteen children (4 boys, 12 girls) with a mean age of 11.2 years at the time of the procedure underwent ex-vivo surgery at the university hospital of Saint-Etienne between 1992 and 2008. Acetylsalicylic acid was used for antiplatelet therapy in the postoperative period, without routine anticoagulation. The mean follow-up period was 15 years. The clinical course of these patients was retrospectively reviewed in adulthood and the results analyzed. RESULTS: The children were treated with a mean of 2.37 drugs per patient, and the mean preoperative blood pressure of the entire patient population was 151/89 mmHg. Mean preoperative creatinine clearance was 80 ml/min/1.73 m2. There was no postoperative death. One patient experienced a thrombosis immediately after the surgery, leading to a redo surgery. In this patient diuresis was restarted, but without efficient concentration and filtration, ultimately leading the patient to have a renal transplant after 1 year. At the end of the follow-up period, eight of the 16 patients (50%) were cured and the others were improved. At the last follow-up the mean blood pressure was 127/70 mmHg, and the mean number of drugs per patient was 0.68. The mean creatinine clearance at last follow-up was 104.3 ml/min/1.73 m2. Three patients had secondary procedures, with two undergoing percutaneous angioplasty (at postoperative months 9 and 12, respectively) and one having an hepatorenal bypass at postoperative year 4. Primary patency was 12/16 (75%); primary assisted patency was 15/16 (94%); secondary patency was 16/16 (100%). CONCLUSION: This study shows that renal autotransplantation has good and stable long-term results and is an effective conservative strategy for treating renovascular hypertension in children, thus avoiding nephrectomy.

Prognostic Value of Aortoiliac Calcification Score in Kidney Transplantation Recipients.

BACKGROUND: Kidney recipients are increasingly older with arterial disease and extended arterial calcifications. In a kidney transplantation population, the prognosis value of aortic and iliac calcifications remains poorly explored. We aimed to assess the impact of pretransplantation aortoiliac vascular calcifications on patients, grafts survival, and cardiovascular events. METHODS: This retrospective study included kidney transplantation patients from 2006 to 2012 for whom we had available presurgery abdominal computed tomography results (n = 100). We designed a score to quantify aortoiliac calcifications. Primary end points were patient and graft survival. Secondary end points were renal function and cardiovascular morbidity. Predictive performances of calcification score were assessed using area under receiver-operating characteristic curves. Patients were classified in quartiles depending on global calcium score value. RESULTS: The cumulated rate of death and graft loss was 13% with no significant differences for survival between quartiles. No significant difference was observed in renal function (P = 0.4). Seventeen cardiovascular events were registered with a significant correlation between calcium score elevation and need of cardiovascular surgery during the follow-up (P = 0.01). Global calcium score had a predictive value of 74.5% (95% confidence interval 0.62-0.87) with 71% sensitivity and 73% specificity. CONCLUSIONS: Aortoiliac calcifications do not decrease patient and graft survival. High calcium score predict cardiovascular events and procedures during the follow-up.

Endovascular Repair of a Short Neck Abdominal Aortic Aneurysm with a Physician-Modified Vascutek Anaconda Stent Graft.

An 81-year-old woman was referred for the treatment of a 79-mm-diameter short neck abdominal aortic aneurysm with highly tortuous iliac arteries. She was considered at high risk for open repair and not suitable for standard endovascular repair given the short length of the proximal neck. Delay for a manufactured custom-made fenestrated stent graft was too long given the diameter of the aneurysm. A flexible stent graft was preferred because of severe iliac tortuosity. Endovascular repair was performed using a physician-modified Anaconda stent graft with 1 fenestration for the left renal artery. The technique for device modification and implantation is described. Postoperative course was uneventful and 1-year computed tomography scan showed complete exclusion of the aneurysm sac and patent left renal artery.

Renal Function after Fenestrated or Branched Endovascular Aortic Repair: The Early Impairment Predictive Factors.

BACKGROUND: The purpose of this study was to define predictive factors of early renal impairment after fenestrated or branched endovascular aortic repair (FEVAR or BEVAR) for aortic aneurysm. METHODS: Eighty-two patients underwent FEVAR or BEVAR for aortic aneurysm from January 2008 to December 2014. The primary end point was postoperative renal impairment on day 15 (D15). Renal impairment was defined as a 25% decrease in the glomerular filtration rate (GFR) and a GFR < 60 mL/min/1.73 m2 according to the Risk Injury Failure Loss and End-Stage criteria. Univariate and multivariate analyses were used to determine variables associated with early postoperative renal impairment. RESULTS: Seventy-seven of the 82 patients had a creatinine level on D15 and were included in this study, including a total of 145 target renal arteries. A preoperative GFR < 60 mL/min/1.73 m2 was present in 16 (20.8%) patients. On D15, 8 (10.4%) patients had an early postoperative renal impairment and 21 (27.3%) patients had a GFR < 60 mL/min/1.73 m2. A single patient had immediate postoperative dialysis for 10 days. "Perirenal hematoma" and "preoperative renal length under 100 mm" were significantly associated with the occurrence of the renal impairment after mutual adjustment in multivariate analysis (P < 0.001 and P = 0.01). No significant association was found between preoperative renal insufficiency combining all stages or with a GFR < 60 mL/min/1.73 m2 and early renal impairment after surgery (P = 0.096 and P = 0.263). CONCLUSION: The presence of a reduced preoperative renal length and the postoperative occurrence of a perirenal hematoma are predictive factors of renal impairment on D15 for patients treated with FEVAR or BEVAR.

Finite element analysis of the mechanical performances of 8 marketed aortic stent-grafts.

PURPOSE: To assess numerically the flexibility and mechanical stresses undergone by stents and fabric of currently manufactured stent-grafts. METHODS: Eight marketed stent-graft limbs (Aorfix, Anaconda, Endurant, Excluder, Talent, Zenith Flex, Zenith LP, and Zenith Spiral-Z) were modeled using finite element analysis. A numerical benchmark combining bending up to 180° and pressurization at 150 mmHg of the stent-grafts was performed. Stent-graft flexibility, assessed by the calculation of the luminal reduction rate, maximal stresses in stents, and maximal strains in fabric were assessed. RESULTS: The luminal reduction rate at 90° was <20% except for the Talent stent-graft. The rate at 180° was higher for Z-stented models (Talent, Endurant, Zenith, and Zenith LP; range 39%-78%) than spiral (Aorfix, Excluder, and Zenith Spiral-Z) or circular-stented (Anaconda) devices (range 14%-26%). At 180°, maximal stress was higher for Z-stented stent-grafts (range 370-622 MPa) than spiral or circular-stented endografts (range 177-368 MPa). At 90° and 180°, strains in fabric were low and did not differ significantly among the polyester stent-grafts (range 0.5%-7%), while the expanded polytetrafluoroethylene fabric of the Excluder stent-graft underwent higher strains (range 11%-18%). CONCLUSION: Stent design strongly influences mechanical performances of aortic stent-grafts. Spiral and circular stents provide greater flexibility, as well as lower stress values than Z-stents, and thus better durability.

In vivo microscopy of targeted vessel occlusion employing acoustic droplet vaporization.

OBJECTIVE: Embolotherapy is a potential means to treat a variety of cancers. Our approach-gas embolotherapy-introduces the droplets upstream from the tumor and then acoustically activates them to form bubbles for occlusion-a process known as ADV. We wanted to provide the first optical documentation of ADV, lodged bubbles, or vessel occlusion in vivo. METHODS: We used the rat cremaster muscle for in vivo microscopy. Perfluorocarbon droplets were administered into the aortic arch. Ultrasound exposures in the cremaster induced vaporization. The cremaster was examined pre- and post-exposure for ADV-related effects. Two sets of experiments compared the effect of exposure in the capillaries versus the first order arteriole. RESULTS: Bubbles that lodge following capillary exposure are significantly larger (76 µm mean length, 36 µm mean diameter) than those following feeder vessel exposure (25 µm mean length, 11 µm mean diameter). Despite the differing sizes in bubbles, the ratio of bubble length to the hydraulic diameter of all lodged bubbles was 2.11 (±0.65; n = 112), which agrees with theoretical predictions and experimental observations. CONCLUSIONS: Our results provide the first optical evidence of targeted vessel occlusion through ADV. These findings could lay the groundwork for the advancement of gas embolotherapy.

Carotid artery surgery: high-risk patients or high-risk centers?

BACKGROUND: Carotid angioplasty and stenting has been proposed as an alternative to carotid endarterectomy (CEA) in patients deemed as at high risk for this surgical procedure. To date, definitely accepted criteria to identify "high-risk" patients for CEA do not exist. Our objective was to assess the relevance of numerous supposed high-risk factors in our experience, as well as their possible effect on our early postoperative results. METHODS: A retrospective review of 1,033 consecutive CEAs performed during a 5.6-year period at a single institution was conducted (Vascular Surgery Department, St. Etienne University Hospital, France). Early results in terms of mortality and neurologic events were recorded. Univariate and multivariate analyses for early risk of stroke, myocardial infarction, and death were performed, considering the influence of age, sex, comorbidities, clinical symptoms, and anatomic features. RESULTS: The cumulative 30-day stroke and death rate was 1.2%. A total of 10 strokes occurred and resulted in three deaths. The postoperative stroke risk was significantly higher in the subgroup of patients treated for symptomatic carotid artery disease: 2,6% (P = 0,004). Univariate analysis and logistic regression did not show statistical significance for 30-day results in any of the considered variables. CONCLUSION: Patients with significant medical comorbidities, contralateral carotid occlusion, and high carotid lesions can undergo surgery without increased complications. Those parameters should not be used as exclusion criteria for CEA.

Effects of strain rate, mixing ratio, and stress-strain definition on the mechanical behavior of the polydimethylsiloxane (PDMS) material as related to its biological applications.

Tensile tests on Polydimethylsiloxane (PDMS) materials were conducted to illustrate the effects of mixing ratio, definition of the stress-strain curve, and the strain rate on the elastic modulus and stress-strain curve. PDMS specimens were prepared according to the ASTM standards for elastic materials. Our results indicate that the physiological elastic modulus depends strongly on the definition of the stress-strain curve, mixing ratio, and the strain rate. For various mixing ratios and strain rates, true stress-strain definition results in higher stress and elastic modulus compared with engineering stress-strain and true stress-engineering strain definitions. The elastic modulus increases as the mixing ratio increases up-to 9:1 ratio after which the elastic modulus begins to decrease even as the mixing ratio continues to increase. The results presented in this study will be helpful to assist the design of in vitro experiments to mimic blood flow in arteries and to understand the complex interaction between blood flow and the walls of arteries using PDMS elastomer.

Pseudoaneurysms postangioplasty of the renal artery: case reports and review of the literature.

Pseudoaneurysms postangioplasty of the renal artery are a life-threatening complication but are poorly known due to their rarity. The aim of this report is to study this complication through three personal case reports and 10 cases found in a literature review. The data analysis led us to highlight important aspects about four main elements: initial procedure events, time to presentation, symptoms leading to diagnosis, and treatment.

Endovascular treatment for carotid artery stenosis after neck irradiation.

BACKGROUND: To lower the risk of complications, carotid angioplasty and stenting (CAS) has been proposed as an alternative to open surgery for carotid artery stenosis after neck irradiation. However, there are little postoperative data to support the benefits of this strategy. This study evaluated the outcome of CAS in patients who had undergone neck irradiation. METHODS: This retrospective study was conducted at 15 vascular surgery or interventional radiology centers in France between January 1998 and July 2006. A total of 135 patients (115 men) with a mean age of 67 +/- 8 years (range, 43-88) underwent CAS for 149 irradiation-induced lesions. The interval between irradiation and discovery of the lesions was 12 +/- 8 years. Mean diameter reduction was 81% (range, 50%-95%), and stenosis was symptomatic in 34%. Contralateral carotid lesions were observed in 48% of patients, including thrombosis in 18 and stenosis >50% in 53. RESULTS: Technical failure occurred during CAS in three cases. The overall technical success rate was 98%. A cerebral protection device was used in 59%. No death, one transient ischemic attack, and two strokes occurred during the first postoperative month. Mean follow-up was 30 months. Six patients were lost to follow-up. Survival rates were 93.9% at 1 year and 75.3% at 3 years. Complications after the first postoperative month included neurologic events in six, carotid thrombosis in nine, and restenosis in 18. The rates of freedom from neurologic and anatomic events were, respectively, 96.2% and 93.2% at 1 year and 93.1% and 85.9% at 3 years. CONCLUSION: The immediate outcome of CAS for irradiation-induced carotid artery stenosis was satisfactory. Medium-term neurologic outcome was acceptable, but the incidence of anatomic events such as thrombosis and restenosis was high. A randomized study is needed to confirm that the outcome of the endovascular and surgical therapy is comparable in this indication.

Predictive Models with Patient Specific Material Properties for the Biomechanical Behavior of Ascending Thoracic Aneurysms.

The aim of this study is to identify the patient-specific material properties of ascending thoracic aortic aneurysms (ATAA) using preoperative dynamic gated computed tomography (CT) scans. The identification is based on the simultaneous minimization of two cost functions, which define the difference between model predictions and gated CT measurements of the aneurysm volume at respectively systole and cardiac mid-cycle. The method is applied on five patients who underwent surgical repair of their ATAA at the University Hospital Center of St. Etienne. For these patients, the aneurysms were collected and tested mechanically using an in vitro bench. For the sake of validation, the mechanical properties found using the in vivo approach and the in vitro bench were compared. We eventually performed finite-element stress analyses based on each set of material properties. Rupture risk indexes were estimated and compared, showing promising results of the patient-specific identification method based on gated CT.

Unusual complication during a percutaneous coronary intervention for a bifurcation lesion using T and Protrusion technique.

Our case reports the first migration of a stent already deployed at high pressure in the main vessel during a 2-stent strategy for a bifurcation lesion using T and protrusion technique. The Kissing balloon was not optimal and could have led to an insufficient strut/cell opening and then to LAD stent pulled back into the artery tree. This case report highlights the importance of an optimal Kissing Balloon in two stent bifurcation technique.